US9050123B2 - Powered surgical system - Google Patents

Abstract

A system for treating tissue includes a device including a first member and a second member arranged to move relative to the first member to treat tissue. The system also includes a processor configured to automatically control movement of the second member relative to the first member using position control methodology. A method of treating tissue includes providing a device having a first member and a second member arranged to move relative to the first member, moving the second member relative to the first member, and automatically controlling the movement of the second member using position control methodology.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/912,067, filed on Apr. 16, 2007, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This invention relates to a powered surgical system.

BACKGROUND

Powered surgical systems typically include a console and associated surgical instruments. The console powers and controls the instruments. The instruments typically include motorized instruments used in surgical procedures such as functional endoscopic sinus surgery, arthroscopy procedures, and the resection of soft and osseous tissues.

SUMMARY

In one general implementation, a system for treating tissue includes a device that includes a first member and a second member arranged to move relative to the first member to treat tissue. The system also includes a processor configured to automatically control movement of the second member relative to the first member using position control methodology.

Implementations can include one or more of the following features. For example, the processor controls movement of the second member relative to the first member such that there is a hold period at least at some occurrences of the aperture being in fluid communication with the tissue environment. The processor computes acceleration and deceleration needed to move the second member between points of a position profile. Each point of the position profile corresponds to a position where the aperture of the device is in fluid communication with the tissue environment. The second member rotates relative to the first member or reciprocates axially relative to the first member. The position control methodology uses a stop position of the second member to compute acceleration or deceleration needed to move between points of a position profile. The position control methodology uses a point of shaft reversal of the second member to compute acceleration or deceleration needed to move between points of a position profile. The first and second members cooperatively define an aperture in the device which depending upon the position of the second member relative to the first member is in fluid communication or is out of fluid communication with a tissue environment.

In another general aspect, a method of treating tissue includes providing a device having a first member and a second member arranged to move relative to the first member, moving the second member relative to the first member, and automatically controlling the movement of the second member using position control methodology.

Implementations can include one or more of the following features. For example, moving the second member relative to the first member alternately places an aspiration opening of the device into fluid communication with or out of fluid communication with a tissue environment. The second member is automatically controlled such that there is a hold period at least at some occurrences of the aspiration opening being in fluid communication with the tissue environment. Automatically controlling the movement of the second member includes computing acceleration and deceleration needed to move the second member between points of a position profile. Each point of the position profile corresponds to a position where the aspiration opening of the device is in fluid communication with the tissue environment. Moving the second member relative to the first member includes rotating the second member relative to the first member. Automatically controlling the movement of the second member includes accelerating and decelerating the second member to cause two rotations of the second member relative to the first member, and then reversing the direction of rotation of the second member. The second member is automatically controlled such that the second member is slowed down or stopped when the aspiration opening is in fluid communication with the tissue environment. Moving the second member relative to the first member includes reciprocating the second member axially relative to the first member. Automatically controlling the movement of the second member using position control methodology includes using a stop position or point of shaft reversal of the second member to compute acceleration or deceleration needed to move between points of a position profile.

In another general implementation, a powered surgical system includes a main control unit including a display, a footswitch connection port, and an instrument port for operation of a surgical instrument device, a power supply housed within the main control unit, and a processor housed within the main control unit and enabling multiple, user-selectable oscillation profiles. The user-selectable oscillation profiles include a velocity controlled mode in which motor speed of a surgical instrument is ramped from zero to a target speed, then back to zero, in a period of time, at which time the direction is reversed, and a position controlled mode in which the motor speed accelerates and decelerates to cause a number of revolutions of the surgical instrument, at which position the direction is reversed.

Implementations can include one or more of the following features. For example, motor speed accelerates and decelerates to cause two revolutions of the surgical instrument, at which position the direction is reversed. The main control unit includes two instrument ports and two footswitch connections ports for simultaneous operation of two instruments. The system can include two instruments connected to the two instrument ports and two footswitches connected to the footswitch connection ports. The two instruments and the footswitches are configurable to communicate configuration, sensory and control data to the main control unit via wired or wireless links. A user interface is configured to receive user-selectable data for controlling operation of the surgical instrument and to display operational parameters associated with the surgical instrument. The wired link includes a bi-directional RS-485 connection or other wired connection. The wireless link includes a Bluetooth connection or other wireless protocol. The system further includes an electro-surgical power generator for providing power to one or more surgical handpieces connectable to the generator.

In another general implementation, a surgical assembly includes a control unit, intelligent peripherals capable of communicating configuration, sensory, and control data to the control unit via wired or wireless links, and a processor housed within the control unit. The processor is configured to enable multiple, user-selectable oscillation profiles including a position controlled mode in which the processor calculates the acceleration or deceleration to move between points of a position profile.

Implementations can include one or more of the following features. For example, an intelligent peripheral includes a motor drive unit configured to communicate position profile data optimized for the geometry of a surgical blade attached thereto. The control unit includes two instrument ports and two footswitch connection ports for simultaneous operation of two surgical instruments.

In another general implementation, a method for controlling movement of a motor shaft based on an algorithm that includes a position profile defining multiple positions of the motor shaft over a period of time includes providing a device having a first member and a second member, the second member coupled to the motor shaft and arranged to move relative to the first member, and moving the motor shaft, which, in turn, moves the second member relative to the first member, between the multiple positions of the position profile within the period of time.

Implementations can include one or more of the following features. For example, the method includes determining the acceleration or deceleration to move the motor shaft between the positions of the position profile. When the second member is moved to each of the multiple positions of the position profile, an aspiration opening cooperatively defined by the first and second members is in fluid communication with a tissue environment. Moving the motor shaft includes controlling electrical power to the motor shaft based on a target shaft position and an actual shaft position. Controlling electrical power includes inputting the target shaft position and the actual shaft position to a discrete-time proportional-integral-derivative (PID) controller. The method can be performed such that there is a hold period at least at some of the positions of the position profile.

In another general implementation, a surgical system includes a console, a universal drive housed within the console and configured for one or more phase motor control, and a processor housed within the console and enabling multiple, user-selectable oscillation profiles including: a velocity controlled mode in which motor speed of a device is ramped from zero to a target speed, then back to zero, in a period of time, at which time the direction in reversed; and a position controlled mode in which the motor speed accelerates and decelerates to cause a number of revolutions of the device, at which position the direction is reversed.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a surgical system.

FIG. 2A is a schematic illustration of a console of the system ofFIG. 1.

FIG. 2B is a front perspective view of the console ofFIG. 2A.

FIG. 2C is a front view of the console ofFIG. 2A.

FIG. 2D is a rear view of the console ofFIG. 2A.

FIG. 3 is a side perspective view of a surgical instrument.

FIG. 3A is an illustration of perspective views of powered instruments.

FIG. 4A is a perspective view of a footswitch of the system ofFIG. 1.

FIG. 4B is a schematic view of an alternative footswitch.

FIG. 5 is an illustration of a control screen of the console ofFIG. 2A.

FIG. 6 is an illustration of an architecture of an application of the console ofFIG. 2A.

FIG. 7 is an illustration of a graphic included in a control screen of the console ofFIG. 2A.

FIG. 8 is an illustration of a settings screen of the console ofFIG. 2A.

FIGS. 9A-9C are illustrations of settings screens of the console ofFIG. 2A.

FIG. 10 isexample process1000 for moving a blade of an instrument.

FIGS. 11A-11E illustrate position profiles for a blade of an instrument.

FIG. 12A illustrates a velocity control technique for controlling electrical power to a motor.

FIG. 12B illustrates a position control technique for controlling electrical power to a motor.

FIG. 13 illustrates a settings screen of the console ofFIG. 2A.

FIG. 14 illustrates a settings screen of the console ofFIG. 2A.

DETAILED DESCRIPTION

Referring toFIG. 1, asurgical system100 includes aconsole110, one ormore instruments132,134 driven by theconsole110, a fluid management system, such aspump150 that provides pressure during surgical procedures, an electro-surgical generator160 that powers handpieces used in, for example, temperature control, cutting, and ablation applications, and aninstrument rack170.

Theconsole110 includes twoinstrument ports112 and114, to whichinstruments132 and134 are respectively connected. Theinstruments132 and134 can include motor drive units and powered arthroscopic instruments, such as drills, wire/pin drivers, and sagittal saws. These instruments are used in, the resection of soft and osseous tissues in large and small articular cavities, for example. The instruments also can be used in Functional Endoscopic Sinus Surgery (FESS). Theconsole110 allows for simultaneous use and control of theinstruments132,134. Theinstruments132 and134 can include two motor drive units, two powered instruments, or a combination of a motor drive unit and powered instrument. Theinstrument port112 and theinstrument port114 are also respectively referred to as “Port A” and “Port B.”

As described in more detail below, theconsole110 permits a user to manage the movement of one or more instruments connected to theconsole110 via a user-programmable oscillation mode algorithm. Theconsole110 supports two oscillation modes: (1) a velocity-controlled mode in which motor speed is ramped from zero to a specified target speed and then ramped from the target speed to zero again in a specified time; and (2) a position-controlled mode in which the motor accelerates and decelerates to specified positions in specified periods of time to enable reversal of direction to return to a starting position. The position control methodology provides enhanced system precision and flexibility because rather than using shaft position to signal (trigger) a control algorithm when to stop or reverse direction (e.g., a velocity control algorithm), shaft position is the input to a position control algorithm. Thus, the stop position or point of shaft reversal is known in advance by the control algorithm as it computes the acceleration or deceleration to move between the points of the position profile.

Theconsole110 also includes afootswitch connection port116 to which afootswitch140 is connected. Thefootswitch140 is configured to drive either of theinstruments132 and134. In further implementations, theconsole110 can include an additionalfootswitch connection port116ato which anadditional footswitch140ais connected. The footswitch140acan be configured to drive either of the other of theinstruments132 and134. As discussed in greater detail with respect toFIGS. 5,8,9, and13, theconsole110 also displays user prompts and system diagnostic text on a liquid crystal display (LCD)120. Theconsole110 also includes aport117 through which theconsole110 is connected to a power source, such as a wall receptacle at 120 volts AC, 15 A, and 50-60 Hz, or other voltages.

As discussed in more detail below, theconsole110 provides support for intelligent peripherals, such as theinstruments132 and134 and thefootswitch140. Theinstruments132 and134 and thefootswitch140 communicate configuration, sensory, and control data to theconsole110 via theports112,114, and116, respectively. Theinstruments132 and134 can be connected to theports112 and114 via wired links. Thefootswitch140 can be connected to theport116 via wired or wireless links. Theports112,114, and116 can be bi-directional RS-485 connections. Theport116 can also be a Bluetooth or other wireless protocol connection. All of theports112,114, and116 can be the same type of port (e.g., all RS-485), or theports112,114, and116 can be different types of ports (e.g., the112 and114 ports can both be RS-485 ports and theport116 can be a Bluetooth or other wireless protocol port). The peripherals can be “plug-in-play” such that they can communicate certain data, such as position profile data to theconsole110 once they are connected to one of theports112,114.

Thepump150 is connected to theconsole110 through abi-directional port152 on theconsole110. Thepump150 optionally includes aremote control156, which can be used to control operation of the pump150 (e.g., select pressure settings) during surgical applications. Anexemplary pump150 for use in thesystem100 is a DYONICS 25 Fluid Management System Control Unit, available from Smith & Nephew, Inc. Thepump150 is connected to theinstrument rack170, an example of which is a Procedure Cart with Transformer available from Smith & Nephew, Inc.

The electro-surgical generator160 is also coupled to theinstrument rack170 and to ahandpiece162. Thehandpiece162 is, for example, a single-use or multi-use probe for temperature control, cutting, or ablation that emits radio-frequency radiation generated by the electro-surgical generator160. Thehandpiece162 includes integrated cables (not shown) and uses autoprobe recognition to determine the type of probe connected to thehandpiece162. The electro-surgical generator160 is also connected to aninstrument controller164, an example of which is a footswitch used to control the amount of radiation emitted from thehandpiece162.

Referring toFIG. 2A, theconsole110 includes adisplay120,instrument ports112 and114, aconnector board122, amotor controller board123, asystem controller board124, network interfaces126, andserial ports128. Theconsole110 is a software-configurable universal-drive platform that allows simultaneous operation of the motors of two to four or more instruments connected to theconsole110. The motors can be, for example, one-third horsepower and one- to four or higher-phase DC motors. Thedisplay120 is a touch screen liquid crystal display that displays an interface and controls used to set up and operate theconsole110. As discussed in more detail with respect toFIGS. 5,8,9, and13, the interface and controls allow adjustment of settings in theconsole110, such as adjustment of an operating speed of an instrument attached to theconsole110 and selection of oscillation modes for theinstruments132 and134. Thedisplay120 also displays system controls, system information, and procedure information. Theinstrument ports112,114, and116 are configured to receive peripheral devices, such as theinstruments132 and134, and thefootswitch140. Theinstrument ports112,114, and116 are configured for analog and digital inputs and can include an RS-485 or other wired interface.Instrument port116 can alternatively include a Bluetooth interface or other wireless interface.

Theconnector board122 includes interfaces configured to receive circuit boards, such as themotor controller board123 and thesystem controller board124. Themotor controller board123 is a generic slave dual motor controller within a distributed platform, but can include other controllers, such as electro-surgical controllers or other types of motor controller boards. Themotor controller board123 includes a processor, memory, software, and motor drive circuitry. Themotor controller board123 buffers external inputs for use by application software running on thesystem controller board124. The application software sends commands to themotor controller board123 to control the functionality of motors in instruments connected to theconsole110, such as a motor in each of theinstruments132 and134.Multiple controller boards123 could be employed, along with multiple instrument ports on theconsole110 to accommodate, for example, up to four or more independently controlled instruments, such asinstruments132 and134.

Thesystem controller board124, in conjunction with themotor controller board123, controls the motors in theinstruments132,134 connected to theconsole110, by communicating control and parametric data bi-directionally with themotor controller board123. Thesystem controller board124 includes a processor, an operating system, and application software. As discussed in more detail below, a controlling application on thesystem controller board124 in conjunction with thedisplay120 provides graphical status indicators and touch screen control over the motor operation. Thesystem controller board124 also provides status signals to thepump150 in implementations in which thepump150 is connected to theconsole110. Thesystem controller board124 also provides status signals to digital control systems, such as Smith & Nephew Inc.'s CONDOR™ control system and can receive control signals from such digital control systems. These digital control systems enable users to send commands to, for example,instruments132,134, and other medical devices, digital cameras, image management systems and other components using voice commands and a wireless touch panel. The systems also enable real-time streaming audio and video of the procedure over the Internet to classrooms, offices and consulting surgeons in other locations.

Referring toFIGS. 2B and 2C, theconsole110 is enclosed in ahousing180. Afront panel185 of thehousing180 includes thedisplay120, theinstrument ports112 and114, thefootswitch connection port116, and apower switch119. Thepower switch119 initiates procedures to power the console110 (e.g., turn theconsole110 on) and to remove power from the console110 (e.g., turn theconsole110 off). As shown inFIG. 2D, thehousing180 includes arear panel187. Therear panel187 includes thebi-directional port152,serial ports135, a secondbi-directional port136, a thirdbi-directional port137, acase ground138, anetwork interface139, fieldprogrammable ports141,exhaust fans142, and thepower connector117. Thebidirectional port152 connects theconsole110 to a fluid management system, such as thepump150 discussed above with respect toFIG. 1. The secondbi-directional port136 connects theconsole110 to a digital operating room control center. Thecase ground138 is connected to equipment within or external to theconsole110 to bring the equipment to the same electrical ground as thehousing180. Theexhaust fans142 provide cooling for theconsole110, and thepower connector117 allows theconsole110 to be connected to a hospital-grade power cord accessory (not shown). Thepower connector117 is an integral part of theconsole110 and is configured as a receptacle that accommodates the power cord accessory.

FIG. 3 illustrates an exemplarysurgical device300 used in conjunction with theconsole110.Surgical device300 uses a tube-in-tube construction to shear tissue disposed between cutting edges of an elongate outer non-rotatingtubular member310 and an elongate inner rotatingtubular member315, as more fully explained in, for example, U.S. Pat. No. 5,871,493, which is incorporated herein by reference in its entirety. Thesurgical device300 includes aMDU325 coupled to themembers310,315 at aninterface305. The outertubular member310 has aproximal end310acoupled to theinterface305 and adistal end310bdefining anopening320 forming a cutting port or window. The innertubular member315 is rotatably received in the outertubular member310 and has a cutting edge (not shown) at its distal end. The innertubular member315 defines an aspiration lumen (not shown) communicating with the cutting edge to remove cut tissue and fluid from a surgical site. When thesurgical device300 is assembled, the cutting edge of the innertubular member315 is positioned adjacent theopening320 of the outertubular member310 and aligns with theopening320 such that during certain portions of the rotation of theinner member315 with respect to theouter member310 theopening320 and the aspiration lumen are either in fluid communication or is out of fluid communication with a tissue environment.

Thesurgical device300 is connected to either the instrument port112 (port A) or the instrument port114 (port B) on thefront panel185 of theconsole110. Once connected to eitherport112,114, theconsole110 automatically detects the presence of thesurgical device300. A variety of disposable straight and curved surgical blades andburrs330 can be inserted into thesurgical device300 at theinterface305 for various surgical applications. Action of theinner member315 is controlled by either the instrument or a footswitch, selecting forward, reverse or oscillate. As will be described in more detail below, theconsole110 provides user-selectable settings for blade speed within minimum and maximum speeds, with the minimum and maximum speeds preprogrammed for each blade type.

Referring toFIG. 3A, powered instruments, such asdrill330 and saw340 can also be used in conjunction with theconsole110. Thepowered instruments330 and340 includetriggers335,345, respectively, used to control operation of thepowered instruments330,340. Thepowered instruments330 and340 can be connected to theinstrument ports112,114 on thefront panel185 of the console viacables337,347, respectively. As discussed above, once connected to theinstrument ports112,114, theconsole110 can automatically detect the presence of thepowered instruments330,340.

Referring toFIGS. 4A and 4B,footswitches410 and450 are shown. Either of thefootswitches410 and450 can be used as thefootswitches140 and140a. Thefootswitches410 and450 are connected to theport116 of theconsole110 through wired or wireless links. Wired communications take place via a RS-485 serial communication port or other wired links or connections, and wireless communications take place via a Bluetooth link and protocol or other wireless links or protocols. Thefootswitches410,450 communicate information about themselves and the position of their pedals to theconsole110. Thefootswitches410,450 control forward, reverse, oscillate, and window lock modes of motor operation. Thefootswitches410,450 control one instrument at a time, and they can be configured to control either the instrument connected to theport112 or the instrument connected to theport114. As described in more detail below, the operation of thefootswitches410,450 can be modified through an interface displayed on thescreen120 of theconsole110. Two modes of operation are available, On/Off and Variable.

Referring toFIG. 4A, thefootswitch410 has threecontrol pedals412,414,416 and twoswitches422 and424. Thepedal412 is considered the “left pedal,” thepedal416 is considered the “right pedal,” and thepedal414 is considered the center pedal. Thepedal412 and the pedal416 default to reverse and forward, respectively. Thus, depressing the pedal412 or the pedal416 causes theconsole110 to supply power to an instrument connected to the console110 (such as the surgical device300) such that theinner member315 of theblade300 is driven in the selected direction. While thepedal412 and the pedal416 default to reverse and forward, respectively, thepedals412,416 can be configured to operate thesurgical device300 in the opposite direction. Thecenter pedal414 is configured to cause thesurgical device300 to oscillate. That is, depression of thecenter pedal414 causes theconsole110 to send position profile control signals to thesurgical instrument325, thus causing theinner member315 to oscillate. Theconsole110 continues to send the control signals to thesurgical instrument325 untilpedal414 is no longer depressed.

When the footswitch is operating in variable or analog mode, the amount of depression of thepedal412,414, and416 determine the percentage of set speed the instrument operates at; 100% of set speed is when the pedal is fully depressed and 0% of set speed (stop) is when the pedal is fully released. When the footswitch is operated in On/Off or digital mode, thepedals412,414, and416 operate the instrument either at 100% of set speed or 0% of set speed (stop). In another implementation, maximum pressure establishes 100% of set speed with each new press of thepedals412,414, and416, and decreasing pressure on thepedals412,414, and416 allows deceleration of the instrument until the instrument stops. Pressing a footswitch pedal signals theconsole110 to accelerate the instrument until the instrument reaches the set speed, and the set speed is maintained until the button is released. Thepedals412,414,416 on thefootswitch410 turn the motor drive on or off in a specific direction. Thus, thefootswitch410 allows thepedals412,414, and416 to control speed as well as blade direction.

Thefootswitch410 also includes twoswitches422,424. Theswitches422 and424 provide control for a Blade Window Lock function, described in more detail below, and a Lavage function, respectively, through a signal that travels from thefootswitch410 to thepump150 through thebidirectional port152.

Referring toFIG. 4B, thefootswitch450 includes twofoot pedals455 and460 to control motor action. Each of thepedals455 and460 is referred to as the forward pedal or the reverse pedal depending upon configuration. Thefootswitch450 includes contact switches (not shown) coupled to each pedal. The contact switches operate in the On/Off mode, such that each press of the pedal455 or the pedal460 starts or stops the instrument. Pressing thepedals455,460 simultaneously causes theconsole110 to send signals to the instrument such that the instrument oscillates.

Referring toFIG. 5, aninterface500 shown on thedisplay120 of theconsole110 provides acontrol screen501 including graphical status indicators and touch screen control over the operation of motors associated with instruments connected to theconsole110. Thecontrol screen501 includes indicator andcontrol sections503 and505, which are respectively associated with the instrument port112 (also referred to as “Port A”) and instrument port114 (also referred to as “Port B”). Thesection503 is on the left hand side of thecontrol screen501 and thesection505 is on the right hand side of thecontrol screen501.

As discussed above with respect toFIG. 2A, thesystem controller board124 communicates control and parametric data bi-directionally with themotor controller board123. Using a set of system interfaces, a controlling application provides the graphical status indicators and the touch screen control, thus allowing a user of theconsole110 to have control over the instruments connected to theconsole110 through thecontrol screen501 ofFIG. 5. The system interfaces are hardware initialization and access functions to resources of thesystem controller board124 that are used by the controlling application. The system interfaces include a bootstrap for Windows CE 4.2, peripheral Windows CE device drivers, a Windows CE USB driver, and a specialized Windows CE device driver, or other applicable system interfaces.

FIG. 6 illustrates anarchitecture600 of the controlling application used with thesystem controller board124. Thearchitecture600 includes three modules, a graphicaluser interface module610, acontrol module620, astring resource module630, and asystem interface640. The graphicaluser interface module610 generates the graphical user interface (such as the control screen501) and the displayed icons, accessories, and accessories controls. Thecontrol module620 notifies the graphical user interface module of a change in state (such as the connection or removal of an instrument from theinstrument port112 or the instrument port114). Thestring resource module630 is a dynamically linked library (DLL) that supplies the graphicaluser interface module610 correct strings depending on the selected language used to present commands in thecontrol display501. Each language that is supported by theconsole110 has an associated DLL that is loaded when theconsole110 is powered on or when the language setting is changed within thecontrol display501. Interactions between the controlling application and themotor controller board123 are handled by thesystem interface640.

Thecontrol module620 continuously monitors the status of theinstrument port112 and theinstrument port114 to determine if an instrument is installed in either or both of theinstrument ports112 and114. When an instrument is detected in theinstrument port112, thecontrol module620 notifies the graphicaluser interface module610 and the graphicaluser interface module610 displays data and accessories associated with the instrument in thesection503 of thecontrol screen501. If the instrument is removed from theinstrument port112, thecontrol module620 notifies the graphicaluser interface module610, which in turn removes the data and accessories associated with the instrument from thesection503 of thecontrol screen501. Similarly, when an instrument is detected as connected to theinstrument port114, thecontrol module620 notifies the graphicaluser interface module610 and the graphicaluser interface module610 displays data and accessories associated with the instrument in thesection505 of thecontrol screen501. If the instrument is removed from theinstrument port114, thecontrol module620 notifies the graphicaluser interface module610, and the data and accessories associated with the instrument are removed from thesection505 of thecontrol screen501.

In certain implementations, one or more of the instruments connected to theinstrument ports112,114 include a motor drive unit (MDU). If a MDU is detected in either or both of theinstrument ports112 and114, thecontrol module620 first determines whether the MDU is capable of hand control. If the MDU is not capable of hand control, a footswitch can be used to control the MDU. If the MDU is capable of hand control, thecontrol module620 monitors the status of the hand controls. Thecontrol module620 also determines whether the connected MDU supports blade recognition, and if the MDU supports blade recognition, thecontrol module620 continuously monitors the blade type. Thecontrol module620 notifies the graphicaluser interface module610 that a MDU has been detected and the graphicaluser interface module610 module displays the data and accessories associated with the MDU on the appropriate side of the control screen501 (e.g., data and accessories associated with a MDU connected to theinstrument port112 are displayed in thesection503 and data and accessories associated with a MDU connected to theinstrument port114 are displayed in the section505).

If thecontrol module620 detects instruments in bothports112,114, the data associated with both instruments is displayed in thecontrol screen501 insections503 and505. The instruments in theports112 and114 are operated independently, however, they can be operated simultaneously. Referring briefly toFIG. 7, if no instrument is detected in theinstrument port112, thesection503 of thecontrol screen501 displays the graphic701, which indicates to the user that no instrument is connected to theport112. Similarly, if thecontrol module620 does not detect the presence of an instrument in theport114, thesection505 of thecontrol screen501 displays the graphic702, which indicates to the user that no instrument is connected to theport114.

Returning toFIG. 5, thecontrol screen501 includes anicon region510, which displaysicons511,512,513, and514 representing items connected to theconsole110. Theicons511,512,513, and514 are displayed upon notification from thecontrol module620 of the connection of an instrument, footswitch, or a connection to some other type of equipment to theconsole110. Theicons511,512,513, and514 also can have various display styles, with each display style representing a state of an instrument represented by the icon or the type of instrument connected. For example, the display style oficons511,512,513, and514 can be a particular color, shading, size, shape, and/or animation that represent a state or a type of instrument connected to theconsole110. Theicons511,512,513, and514 can also be implemented as bitmaps.

In the example shown inFIG. 5, theicon511 is displayed in thesection503 and indicates that a fluid management system or pump150 is connected to theconsole110. A display style of theicon511 can provide additional information about thepump150. For example, if the connected fluid management system is a pump, such as thepump150, thecontrol module620 notifies the graphicaluser interface module610 of the state of the pump. If thepump150 is running, thecontrol screen501 displays and animates a rotating blue icon. Otherwise, the control screen displays a stationary grey icon. If the graphicaluser interface module610 receives an indication from thecontrol module620 that thepump150 has been disconnected from thecontrol module110, theicon511 disappears from thecontrol screen501. Theicon511 also can change format depending on the state of the fluid management system. Theicon511 representing thepump150 can be in thesection503, which corresponds to “Port A,” or thesection505, which corresponds to “Port B,” depending on a mapping specified in a settings menu accessible through thecontrol screen501. Thus, thepump150 can be set to be integrated with an instrument connected to either theinstrument port112 or theinstrument port114. When thepump150 is integrated with the instrument connected to theinstrument port112, thepump150 responds to commands from the instrument and footswitch connected to theinstrument port112. Similarly, if thepump150 is integrated with theinstrument port114, thepump150 responds to commands from the instrument and footswitch connected to theinstrument port114. In some implementations, theLavage button424 works only when thefootswitch410 and thepump150 are connected to the same instrument port.

Additionally, upon notification of connection to a fluid management system, such aspump150, an outgoing serial-communication packet is automatically updated by thecontrol module620 and/or the graphicaluser interface module610. The outgoing serial-communication packet is transmitted to theconnected pump150 through thebi-directional port152 during the initial connection and when a change in data occurs. A “Lavage Toggle” command is also transmitted in the event that a Lavage button is pressed on a connected footswitch that supports this functionality. The outgoing serial-communication packet typically includes a number of bytes in a data structure.

Referring back toFIG. 5, upon notification from thecontrol module620 of the insertion of an instrument, such assurgical device300, motor drive unit (MDU)325, or a powered instrument, such as a drill, saw, etc. into the instrument port112 (e.g., “Port A”) of theconsole110, the graphicaluser interface module610 displays theicons512,514 in thesection503, which correspond to theinstrument ports112,114. If the graphicaluser interface module610 receives a disconnect notification from thecontrol module620 indicating that the instrument has been disconnected from theinstrument port112, theicon512 is removed from theicon region510 or otherwise no longer displayed. Similarly, upon notification from thecontrol module620 of the insertion of a MDU into the instrument port114 (“Port B”), the graphicaluser interface module610 displays a yellow MDU icon (not shown) in thesection505, which corresponds to theinstrument port114. If the graphicaluser interface module610 receives a disconnect notification from thecontrol module620, the MDU icon is removed.

Display of theicon513 indicates that a footswitch has been connected to theconsole110. Theicon513 is removed from the screen when the graphicaluser interface module610 receives a disconnect notification indicating that the footswitch is no longer connected to theconsole110. In the example shown inFIG. 5, theicon513 is displayed in thesection503, which corresponds to the instrument port112 (Port A). If a footswitch is connected to theconsole110, theicon513 is displayed in either thesection503 or thesection505 depending on a mapping selected in a settings menu.

Upon notification from thecontrol module620 of the insertion of an instrument, such as a sagittal saw, in theinstrument port114, the graphicaluser interface module610 displays theicon514 in theicon region505. When the graphicaluser interface module610 receives a disconnect notification from thecontrol module620 indicating that the saw has been disconnected from theinstrument port114, theicon514 is removed from the screen. Similarly, when thecontrol module620 notifies the graphicaluser interface module610 that a saw has been inserted into theinstrument port112, an icon (not shown) representing the saw is displayed in thesection503. The icon representing the presence of the saw in theinstrument port112 and theicon514 representing the presence of the saw in theinstrument port114 can have different display styles while still providing a visual representation that the icons correspond to the same instrument. For example, the icon representing insertion in theinstrument port112 can be yellow and theicon514 can be blue, but the icons can be the same shape and size.

Other types of icons can be displayed to indicate the presence of particular instruments, connections, or tools. For example, upon notification from thecontrol module620 of a digital control system connection, such as Smith & Nephew Inc.'s a CONDOR™ control system, the graphicaluser interface module610 displays an icon (not shown) in the upper right hand corner of thecontrol screen501. If the graphicaluser interface module610 receives a disconnect notification, the icon is removed from thecontrol screen501. Upon notification of a digital control system connection, an outgoing data packet is automatically updated by thecontrol module620 and/or the graphicaluser interface module610 so that when a host requests a packet, the data is updated. When an incoming command from the host is found to be valid, thecontrol module620 and/or the graphicaluser interface module610 is notified of the request and initiates the requested command.

Thecontrol screen501 also includesdirection indicators515aand515b, which indicate a direction or type of motion of the instruments connected to theinstrument ports112 and114, respectively. In the example shown inFIG. 5, the direction indicators include both forward and reverse arrows that point in opposite directions in the center, which indicate that the instruments connected to theinstrument ports112 and114 oscillate. The arrows in thedirection indicators515aand515bpoint to the right when the respective instrument is set to forward motion, and the arrows in thedirection indicators515aand515bpoint to the left when the respective instrument is set to reverse motion.

Thecontrol screen501 also displayscurrent speed settings516aand516bfor the instruments connected to theinstrument ports112 and114, respectively. Thecurrent speed settings516aand516bshow speed and an associated unit ofmeasure517aand517b(for example, rotations per minute as shown inFIG. 5). Thecurrent speed settings516aand516balso include an outline box that can be color coded, and the color can indicate which of theinstrument ports112 and114 is associated with thecurrent speed settings516aand516b.

Thecontrol screen501 can include themaximum speed518 for an instrument connected to theinstrument port112. If an instrument is connected toinstrument port114, the maximum speed for that instrument would be displayed on thesection505 of thecontrol screen501 in a similar manner. The decrement/increment controls519aand519ballow setting of the current speed of thecurrent speed settings516aand516b, respectively. The current speed values can be adjusted within a range of numeric values, and the values are adjusted by pressing the decrement/increment controls519aand519b. Thecontrol module620 receives a notification from the graphicaluser interface module610 of a change in set speed, and thecontrol module620 changes the speed of an instrument connected to the indicated instrument port. When the set speed reaches the minimum or maximum speed for the instrument, the decrement/increment controls519aand519bdisappear. The adjustment of the current set speed can occur automatically at a fixed repeat rate if the decrement/increment button519aor519bis held down for a second or more, and the automatic adjustment ceases when the adjustment button is released or when the current set speed reaches a minimum or maximum for the instrument.

The graphicaluser interface module610 displays the data and accessories associated with the connected MDU on the appropriate side of thecontrol screen501. The data and accessories include thedirection indicators515aand515b, thecurrent speed settings516aand516b, the color-coded outline around thecurrent speed settings516aand516b, the unit ofmeasure517aand517b, themaximum range518, and the decrement adjustment button and theincrement adjustment button519aand519b. Default speed settings and maximum speed is particular to the connected instrument and is determined by specifications of the connected instrument, which can be stored in a table on theconsole110 and accessed by thecontrol module620 and/or the graphicaluser interface module610. For example, a MDU may have a range of forward motion speeds from 100 to 5000 rotations per minute, a default speed of 3000 rotations per minute, the same range of speeds and the same default speed for reverse motion, a speed range of 500 to 3000 rotations per minute in oscillate mode, and a default of 1000 rotations per minute in oscillate mode. If the MDU supports blade recognition, the default values and the ranges are determined taking into account the blade type.

When a MDU is detected, the current mode of operation is set to oscillate by default and the oscillate direction indicators are displayed in white on theappropriate direction indicator515aand515bdepending on which instrument port into which the MDU was connected. Pressing a forward hand control button on the MDU causes thecontrol module620 to notify the graphicaluser interface module610, and the forward direction indicators are displayed in theappropriate direction indicator515aor515b(e.g., all arrows point to the right in the appropriate direction indicator). Similarly, if a reverse hand control button is pressed on the MDU, reverse direction indicators are displayed on theappropriate direction indicator515aor515b(e.g., the direction indicator shows all arrows pointing to the left). If the forward hand control button on the MDU is held down for a second or more, the speed of the MDU alternates between two speeds while displaying the forward direction indicators in theappropriate direction indicator515aor515b. Releasing the forward button on the MDU results in the current speed setting being the most recent set speed value. Similarly, holding the reverse hand control button for a second or more results in the set speed alternating between two speeds while the reverse direction indicators are displayed in theappropriate direction indicator515aor515b.

If an oscillate hand control button is pressed on the MDU, thedirection indicator515aor515bcorresponding to the instrument port in which the MDU is connected displays oscillate direction indicators (e.g., left- and right-pointing arrows are shown with the arrowheads pointing in opposite directions in the center of the direction indicator). Additionally, if the oscillate hand control button on the MDU is pressed and held down for about a second or more, thecontrol module620 will notify the graphicaluser interface module610 and thedirection indicator515aor515bshows the window-lock direction indicators (e.g., left- and right-pointing arrows are shown with arrowheads coming together in the center of the direction indicator.

Additionally, when a MDU is detected, thecontrol screen501 can display the maximum rotations per minute (RPM) or other unit of measure, depending upon the current MDU mode of operation, in the appropriate unit ofmeasure display517aand517b. If the current mode of operation of the MDU is forward, reverse, orOscillate Mode 1, the unit of measure is RPM and the maximum RPM for the MDU is displayed in518. If the current mode of operation of the MDU isOscillate Mode 2, the unit of measure is rate rather than RPM.Oscillate Mode 1 is a velocity-controlled method of ramping motor speed from zero to a specified target speed and then ramping the motor speed from the target speed to zero again in a specified period of time.Oscillate Mode 2 is a position-controlled method of ramping motor speed in which the motor accelerates and decelerates to a specified position in a specified period of time and then reverses direction and returns to the starting position.Oscillate Mode 1 is available for all MDUs, but neither mode is typically available for powered instruments such as drills and saws, which run unidirectionally.

If thecontrol module620 determines that the MDU is in a running state, the graphicaluser interface module610 is notified by thecontrol module620 and thecontrol display501 is updated to reflect the running state. For example, the color of the arrows in thedirection indicators515aand515bcan be colored green and the background color of the appropriate current speed setting516aor516bcan change. If the MDU is turned off, the background color of the appropriate current speed setting516aor516bchanges to reflect the new state of the MDU.

If a powered instrument is connected to theconsole110, thecontrol module620 monitors the status of the hand controls on the powered instrument to determine if the powered instrument supports direction control. The powered instrument can be, forexample drill330 or saw340 (FIG. 3A). A drill may support forward and/or reverse operation, and a saw supports a mechanical oscillate mode of operation. Thecontrol module620 notifies the graphicaluser interface module610 that a powered instrument has been detected in theconnection port112 and/or114, and the graphicaluser interface module610 displays the data and accessories associated with the powered instrument on the appropriate side of the control screen510 (e.g., insection503 or505).

For powered instruments,sections503 and505 includedirection indicators515aand515b, and thedirection indicators515aand515bdisplay a percentage of full speed associated with the current set speed, a color coded outline around the current set speed, and the decrement/increment controls519aand519b. The percentage of full speed is adjusted by pressing the decrement/increment controls519aor519b, and the decrement/increment controls519aand519bdisappear when set speed reaches the maximum or minimum for the powered instrument. The default speed range is 10%-100% in ten-percent increments, and the default setting is 50% of full speed for the drill and 100% of full speed for the saw. The percentage of full speed is adjusted automatically at a fixed percentage amount if either the increment or decrement button is held down. The adjustments cease when the decrement/increment control519aor519bis released or when the percentage of full speed has reached its minimum or maximum.

A trigger located on the powered instrument can be used to activate it. The amount of depression of the trigger determines the actual speed of the powered instrument, and the trigger can be used to vary the speed of it. When the trigger is released, the powered instrument is stopped, and fully depressing the trigger results in the speed of the powered instrument being a percentage of full speed of the powered instrument as shown in a currentset speed indicator516aor516b. If a footswitch is used, trigger operation of the powered instrument is suspended until the footswitch releases control, and trigger operation of the powered instrument blocks the footswitch until the trigger releases control. When a powered instrument is connected to theinstrument port112 or114, the controlling application ignores the Window Lock and Lavage footswitch button functions. Adaptive trigger calibration captures the maximum and minimum analog values measured during use of the powered instrument and expands an active trigger ON region accordingly. To prevent locking in an out-of-range value, if a powered instrument is connected to theconsole110 with the trigger depressed, the ON limit (TriggerMin) is reset with the OFF limit (TriggerMax) leaving an initial ON region of 15 ADC counts. The ON region is allowed to re-expand during normal trigger operation. A small hysteresis band (e.g., 15 ADC counts), applied to the decision to recalibrate OFF limit (TriggerMax) and reset the ON limit (TriggerMin), minimizes unnecessary recalibrations.

A deadband bounding the trigger ON region at both limits serves a dual purpose. On the TriggerMax side, it accommodates the voltage change incurred by lever trigger units from the sliding magnet trigger lock mechanism. Here, this band is required to allow the release of the trigger lock, causing a corresponding drop in trigger voltage, without inadvertent motor actuation. On the TriggerMin side, it prevents motor velocity changes at the maximum trigger position caused by mechanical slop in the trigger assembly.

Additionally, if theconsole110 detects a problem or failure, theconsole110 displays a warning (not shown) on thecontrol screen501. For example, the warning can be a yellow box located near the bottom of thecontrol screen501. Touching the displayed warning opens a full description of the error or failure that caused the warning. A button (such as an “OK” button) can be pressed to close the warning message and return to thecontrol screen501. When theconsole110 encounters a system fault, theconsole110 stops operation of the attached instruments, sounds an alarm, clears thecontrol screen501, and displays a fault message.

Thecontrol display501 also includes a change mode control orsettings button522, selection of which allows a user to specify preferences for oscillation modes, footswitches, pump interface, language, etc. If a MDU is not active, connected to theconnection port112 or114, supports two oscillation modes and was last active in oscillate mode or was just connected, thechange mode control524 is displayed. Selection of thechange mode control524 will toggle the MDU between oscillate modes as provided in more detail below. Thecontrol display501 also includes asettings control522, selection of which produces a settings menu through which a user can configure various settings of theconsole110 once all of the instruments and other devices have been connected to theconsole110. The settings control522 is active whenever the MDUs and powered instruments connected to theconsole110 are not running.

Referring toFIG. 8, aninterface800 shown on thedisplay120 shows asettings screen801 that allows users to specify preferences and parameters for the operation of peripherals connected to console110. The settings screen801 is displayed in response to a selection of the settings control522 (FIG. 5). The settings screen801 includes anoscillate mode control802, afootswitch control804, apump interface control806, asystems information control808, and alanguage control810. The settings screen801 also includes ablade mode control812, blade resettext813, blade reset controls814 and816, and a completion or “Done”control818.

Theoscillate mode control802 allows the user to program oscillate mode settings. Theconsole110 supports two oscillation modes and these two modes may be referred to asOscillate Mode 1 andOscillate Mode 2.Oscillate Mode 1 is a velocity-controlled method of ramping motor speed from zero to a specified target speed and then ramping the motor speed from the target speed to zero again in a specified period of time.Oscillate Mode 2 is a position-controlled method of ramping motor speed in which the motor accelerates and decelerates to move a motor shaft to specified positions in specified periods of time to enable reversal of direction to return to the starting position. Oscillation can be based on a desired time period (Mode 1) or a set number of revolutions (Mode 2).Oscillate Mode 1 is the default oscillation mode.

Referring toFIG. 9A, selection of theoscillate mode control802 opens anoscillate mode screen910, which allows adjustment to the oscillation profile of the instrument connected to either the instrument port112 (“Port A”) or the instrument port114 (“Port B”). The screen that opens depends upon the last oscillate mode used for the instrument port selected. Acontrol912 allows the user to customize the oscillate mode activated for the instrument connected to the instrument port112 (e.g., “Port A”), and acontrol914 allows the user to customize the oscillate mode activated for the instrument connected to the instrument port114 (e.g., “Port B”). If the surgical instrument attached to the selected port will operate in eitherOscillate Mode 1 orOscillate Mode 2, pressing Adjust opens either theMode 1 orMode 2 screen, depending on which was last used for that port. Selection of a done control916 returns the user to the previous screen, thesettings screen801.

Selection of thePort A control912 or thePort B control914 from theoscillate mode screen910 launches oscillate mode onescreen920 (FIG. 9B) ifOscillate Mode 1 was last used for that port. As noted above,Oscillate Mode 1 is based on a time interval. Atime adjustment control925 allows a user to set the number of seconds (e.g., the time interval) an instrument takes to make one forward or reverse period of oscillation as displayed indisplay924. For example, the time may be adjusted in increments of 0.1 seconds by selecting thetime adjustment control925. When the time has reached the minimum or maximum of the instrument's oscillation range, thetime adjustment control925 disappears. In the example shown inFIG. 9B, the range of oscillation is 0.30 to 1.0 seconds for an oscillation period. Selection of thedefault control926 restores the time to a default value. Selection of a cancelcontrol927 returns the user to theoscillate mode screen910, without changing the current settings, and selection of aset control928 notifies thecontrol module620 to save the current settings and to use the newly selected value before returning the user to oscillatemode screen910.

Selection of the Port A control921 or thePort B control914 from theoscillate mode screen910 launchesOscillate Mode 2 screen930 (FIG. 9C) ifOscillate Mode 2 was last used for that port. As discussed above,Oscillate Mode 2 is based on a number of revolutions a blade completes before reversing directions. For example, theOscillate Mode 2 can be set such that the blade completes 1 or 2 revolutions before reversing directions. TheOscillate Mode 2screen930 includes anadjustment control935 to set a number of revolutions to rotate in each direction before reversal during oscillation. The number of revolutions is adjusted in increments of 1 revolution by pressing theadjustment control935 and is displayed indisplay934. The range of the adjustment is one to two revolutions. When the number of revolutions has reached the minimum or maximum of the range of possible revolutions for the instrument, theadjustment control935 disappears. The default number of revolutions is restored by selecting thecontrol936. Selection of a cancelcontrol937 returns the user to theoscillate mode screen910, without changing the current settings, and selection of aset control938 notifies thecontrol module620 to save the current settings and to use the newly selected value before returning the user to oscillatemode screen910.

Referring toFIG. 10, anexample process1000 for moving a blade of an instrument operating inOscillate Mode 2 to a new position is shown. Blade Window Lock is used to set the stop position of the inner rotating blade (e.g.,inner member305 ofFIG. 3) relative to theopening320 of theouter member310, as described in U.S. Pat. No. 5,602,449, which is incorporated by reference herein in its entirety. Window Lock is used in the position control methodology discussed herein to determine the initial position of the position profile (P_i). A position of a motor output shaft is determined from the motor's three armature position Hall Effect sensors and a gearhead ratio. Target motor shaft positions are calculated from a position profile that is defined by an array of coordinates in the form: percentage of time elapsed, and position, with position being defined in revolutions of output shaft. The period of time (in seconds) to transact one complete move profile is stored in theconsole110. The position profile can be stored in a data structure that includes the percentage time coordinate, the revolution distance coordinate (which can specify distance as a number of revolutions), and a count variable that includes a number of point pairs defining the profile. Profiles that repeat end in the position from which the profile began to prevent creep (unless that is the intent).

To move the blade of an instrument operating inOscillate Mode 2, it is determined whether a target position has been reached (1002). The target position can be a position specified in a coordinate of the position profile. If the target position has been reached, parameters to move to the next point in the profile are determined (1004). In particular, the time in seconds to move from the current position (P_k) to the next position (P_k+1), the distance from the current position (P_k) to the next position (P_k+1), and an acceleration to move from the current position to the next position are determined. Again, the current position (P_k) can be any arbitrary position within the move position profile. If the target position has not been reached, an incremental target distance between the current position and the next position is determined (1006). The current velocity is saved, a new velocity is calculated for the next point from acceleration and time, and a new target position is calculated from velocity and time. Table 1 shows an example position profile.

	TABLE 1
	Point	% time	distance (number of revolutions)

	Pi	0	0
	Pi+1	5	1
	Pi+2	10	2
	Pi+3	50	2
	Pi+4	55	1
	Pi+5	60	0
	Pi+6	100	0

In the example shown in Table 1, P_iis the initial position, and each point corresponds, in this example, to the window open position. For a complete move profile of 0.50 seconds, the first and second forward revolutions each occur in 0.025 seconds (5% time for each revolution), followed by a hold period with the window open of 0.2 seconds (40% time), followed by two reverse revolutions each in 0.025 seconds (5% time for each revolution), followed by a hold period with the window open of 0.2 seconds (40% time). The cycle is then repeated. The hold periods act to reduce clogging of the blade and enhance resection by evacuating material out of the blade and then pulling more material into the blade to be cut in the next cycle.

The number of revolutions prior to direction reversal can be other than two revolutions, for example, one or three revolutions. The hold period can be other than 40% of the time for the complete move profile, for example, in the range of 10% to 40%. The optimum hold period is a function of the suction rate and the length of the blade. Furthermore, different profiles can be employed for different tissue types and/or for different blades. Table 2 shows an example of a simple triangular oscillate profile (Mode 2). In the example shown in Table 2, point of direction reversal occurs at P_i+2, since the distance (number of revolutions) begins to decrease beyond that point.

	TABLE 2
	Point	% time	distance (number of revolutions)

	Pi	0	0
	Pi+1	25	1
	Pi+2	50	2
	Pi+3	75	1
	Pi+4	100	0

Position control provides for high speed, complex blade motions. Referring toFIGS. 11A-11E, examples of various shaft position (S) vs. percentage of time (T) profiles are shown. Each of the profiles has unique and beneficial cutting attributes when matched with different tissue types and blade styles. The initial position for rotary or reciprocating blades can be set using window lock. The attributes listed below are non-limiting examples for a window lock position of open.FIG. 11A shows an oscillation profile with two forward and two reverse rotations per cycle and a 0.1 second period. Such a profile provides increased soft tissue resection rates.FIG. 11B shows a profile that is similar to the profile ofFIG. 11A with the addition of a mini-oscillation cycle at the window open position at the end of the forward portion of the cycle. Profiles such as the profile shown inFIG. 11B are suited for biting off harder fibrous tissues such as an ACL stump.FIG. 11C shows a profile that corresponds to the hold profile discussed above. A profile such as the profile ofFIG. 11C is suitable for reducing soft tissue clogging in toothless style blades.FIG. 11D shows a profile that is particularly adapted for a reciprocating style blade. The profile shown inFIG. 11D has an initial slow distal motion and speeds up near the distal-most portion of the stroke to cut tissue. The profile ofFIG. 11D is suitable for cutting, for example, the meniscus.FIG. 11E shows a profile that illustrates the aperiodic motion capability of the position control methodology. Although not illustrated, profiles containing negative positions are fully supported.

Referring toFIG. 12A, the target shaft position and actual shaft position become the inputs to a discrete time proportional-integral-derivative controller (PID) velocity control algorithm that controls the electrical power necessary to keep the motor shaft position on target and cause the motor to move at a particular velocity. Gain variables are used to scale values included in control blocks, and the values included in control blocks are summed and piped through filters to produce an output to the motor. Setting appropriate coefficients to zero allows the same variable structure and PID function to be used for both position and velocity control, as well as for different types of motors. Avelocity command1205 can include a target velocity set by a user of theconsole110. The target velocity can be set in the user interface discussed above.

Thevelocity profiler1210 determines increments and decrements of velocity of the motor over discrete time periods, and atarget velocity1215 is a velocity determined to move the motor to a target position at a particular velocity. Anacceleration PWM module1220 adds inertial compensation to the velocity. In particular, the acceleration PWM module adds a boost to accelerate a high-inertial load. Afeed forward module1225 is an open-loop estimate of how fast the motor would run without a load. Thefeed forward module1225 applies voltage to the motor and translates voltage applied to the motor to the speed of the motor. ThePWM controller1230 acts as a torque limit and limits torque on the motor to a predefined threshold. Aload compensation module1235 indicates load on the motor in current and compensates for the load on the motor. Theoutput module1240 includes the resistance in the motor, torque and voltage constants, inertia of the motor, and inductance of the motor. Theoutput module1240 also indicates measurable parameters of the motor, including the velocity, current in the motor, and position of the motor. The actual velocity of the motor and the target velocity of the motor are input into aPID filter block1250, and P, I, and D coefficients are determined in thefilter block1250.

Referring toFIG. 12B, a PID position control algorithm works similarly to the PID velocity control algorithm discussed with respect toFIG. 12A. In the position control algorithm, the coefficients of thefeed forward module1225 are set to zero. Instead of receiving a velocity command, an array ofpositions1260 is provided to aposition profiler1265. The array of positions is positions in a position profile of the instrument (such as the profiles shown inFIGS. 11A-11E). Atarget position1270 is compared to an actual position at thePID filter block1250.

In addition to rotating blades, the position control methodology can also be applied to an axial, reciprocating blade. Here again, the movement of the blade can be controlled such that there is a hold period when the reciprocating blade is in its distal position with the window open. The position control methodology can also be used to slow down or stop a rotating blade in a predetermined window position when the blade is running in forward or reverse mode.

The position control methodology provides system precision and flexibility. Rather than using knowledge of shaft position to signal (trigger) a control algorithm when to stop or reverse (a velocity control algorithm), knowledge of shaft position is the input to the position control algorithm. Therefore, the stop position or point of shaft reversal is known in advance by the control algorithm as it computes the acceleration needed to move between the points of the position profile. The velocity control algorithm regulates the speed in which the shaft rotates asynchronously to its position. In a velocity control algorithm, the independent variables (inputs to, and controlled by, the control algorithm) are time, acceleration, and velocity, with the dependent variable (consequence of the control algorithm) being position. In the position control algorithm, the independent variables (inputs to, and controlled by, the control algorithm) are time and position, with the dependent variables (consequences of control algorithm) being velocity and acceleration.

Referring again toFIG. 8, thefootswitch control804 allows the user to configure the footswitch. Selecting thefootswitch control804 button from the settings screen will launch thefootswitch screen1301 shown inFIG. 13. Thefootswitch screen1301 permits the user to configure the way the footswitch works. The graphicaluser interface module610 is notified by thecontrol module620 of a selection of aport control1304, ahand control override1306, or afootswitch mode control1308. Selection of a cancelcontrol1310 returns to the settings screen801 without changing the current setting. Selection of theset control1312 notifies thecontrol module620 to save the current settings and to use the newly selected settings before returning to thesetting screen801. Thefootswitch screen1301 includes theport control1304, which provides controls for assigning the footswitch to either instrument port112 (e.g., Port A) or instrument port114 (e.g., Port B). The currently selected port is indicated by shading in the example shown inFIG. 13. The footswitch drives the instrument connected to the selected port.

Thefootswitch screen1301 also includes ahand control override1306, which allows a hand control override feature of an instrument to be enabled or disabled. Thehand control override1306 allows the user to set the primary controls for controlling the motor of a connected MDU, and the current override setting is shown by shading. When the handcontrol override control1306 is set to On, only the footswitch operates the instrument, and hand controls for that instrument do not operate. When the handcontrol override control1306 is set to Off, either the hand controls or the footswitch can be used to operate the instrument. However, only one source of control can be used at one time (e.g., at a particular time, either the footswitch or the hand controls can operate the instrument).

Thefootswitch screen1301 also includes thefootswitch mode control1308, which allows the user to change the forward and reverse pedal assignments on the footswitch. However, if theconsole110 detects that the footswitch does not support re-mapping of the forward and reverse pedals, the user is not allowed to change the forward and reverse pedal assignments. For footswitches that support re-mapping of the forward and reverse pedals, selection of the “L” button will map the forward mode of operation to the left foot pedal of the footswitch. Selection of the “R” button will map the forward mode of operation to the right foot pedal of the footswitch.

Thefootswitch screen1301 also includes amode selection control1309. Themode selection control1309 allows the user to select to use the footswitch in an On/Off mode (which can be the digital footswitch mode discussed above) or a variable mode (which can be the analog footswitch mode discussed above). Briefly, in On/Off mode, depressing a footswitch pedal causes a instrument connected to theconsole110 and controlled by the footswitch to operate at full set speed, and releasing the footswitch pedal turns the instrument off. Pressing a pedal of a footswitch that is operating in Variable mode causes the instrument speed to be adjusted based on pedal pressure. If theconsole110 detects a footswitch that does not support variable mode operation, such as a Low Profile (On/Off) or Pedal-Style footswitch, themode selection control1309 does not appear on thefootswitch screen1301, and the footswitch operates in the On/Off mode. In the example shown inFIG. 13, the footswitch supports variable mode operation, thus themode selection control1309 is displayed, and themode selection control1309 can be used to select to operate the footswitch in either the On/Off or Variable mode. In the example shown, the user has selected to operate the footswitch in variable mode, and a button corresponding to the variable footswitch mode is shaded to indicate that variable mode is the active footswitch mode.

Thefootswitch screen1301 also includes a cancelcontrol1310 and aset control1312. Selection of the cancelcontrol1310 returns the user to the settings screen801 without changing the current setting. Selection of theset control1312 saves the current footswitch settings and returns the user to thesettings screen801.

Referring again toFIG. 8, selection of thepump interface control806 causes a pump interface screen1401 (FIG. 14) to appear. The pump or fluid management system operates from the MDU connected to the port to which the pump is assigned. For example, and referring toFIG. 14, for the pump to work with a MDU connected to the instrument port112 (“Port A”), “Port A” is selected in aport control box1403. The selected port is shaded to indicate selection of the port. In the example shown, Port A is selected, thus the pump works with an instrument connected toinstrument port112. Selection of the “Port B” button in theport control box1403 results in the pump being assigned to work with the instrument connected to the instrument port114 (“Port B”) of theconsole110. Thepump interface screen1401 also includes a cancelcontrol1405, selection of which returns the user to the settings screen801 without changing the current settings. Theset control1407 saves the current settings shown in thepump interface screen1401 and returns the user to thesettings screen801.

Selection of thesystem information control808 ofFIG. 8 causes a display of general information associated with theconsole110, such as the product name, product reference number, software versions, application versions, and motor controller version. Thelanguage control810 allows the user to specify the language in which commands and information are displayed. For example, selection of thelanguage control810 allows the user to select from among various languages such as English, German, French, and Italian.

Theblade mode control812 allows the user to select between using theconsole110 in Blade Recall Mode or Blade Default Mode. When in Blade Recall Mode, theconsole110 can be programmed with custom settings for blade forward speed, reverse speed, oscillate speed (oscillate mode 1) and oscillate rate (oscillate mode 2). If any settings are changed in Blade Recall Mode, the settings are saved until the settings are reset in Blade Recall Mode or the system is restored to default settings. When operating in Blade Default Mode, changes to blade settings are saved until theconsole110 is powered down or the system is reset to Blade Recall Mode. The blade resettext813 and blade reset controls814 and816 are displayed in the settings screen801 when an instrument is in theinstrument port112 or theinstrument port114, respectively. Selection of the donecontrol818 returns the user to thecontrol screen501.

A number of implementations of theconsole110 andsurgical system100 have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the application. For example, while theconsole110 has been described with respect to control of surgical instruments, theconsole110 could be used with handheld instruments in non-surgical settings, and theconsole110 and associated control systems could be used with various types of instruments, both medical and otherwise. In addition, theconsole110 can have just one instrument connected to theconsole110, and the one instrument can be connected to eitherport112 orport114. Theconsole110 can also be referred to as a control unit or a main control unit.

Claims (13)

What is claimed is:

1. A system for treating tissue, comprising:

a device comprising:

a first member, and a second member arranged to move relative to the first member to treat tissue;

a processor configured to automatically control movement of the second member relative to the first member while the first member remains stationary using position control methodology to compute acceleration and deceleration to move the second member to a next incremental point between points of a position profile in specified periods of time and to enable reversal of direction to return to a starting position, the first and second members cooperatively defining an aperture in the device which depending upon the position of the second member relative to the first member is in fluid communication or is out of fluid communication with a tissue environment; and

the processor controlling movement of the second member relative to the first member such that there is a hold period at least at some occurrences of the aperture being in fluid communication with the tissue environment, an optimum hold period determined from a function of a suction rate and a length of the second member.

2. The system ofclaim 1 wherein each point of the position profile corresponds to a position where the aperture of the device is in fluid communication with the tissue environment.

3. The system ofclaim 1 wherein the second member rotates relative to the first member.

4. The system ofclaim 1 wherein the second member reciprocates axially relative to the first member.

5. The system ofclaim 1 wherein the position control methodology uses a stop position of the second member to compute acceleration or deceleration needed to move between points of a position profile.

6. The system ofclaim 1 wherein the position control methodology uses a point of shaft reversal of the second member to compute acceleration or deceleration needed to move between points of a position profile.

7. A method of treating tissue, comprising:

providing a device having a first member and a second member arranged to move relative to the first member;

moving the second member relative to the first member while the first member remains stationary; and

automatically controlling the movement of the second member using position control methodology to compute acceleration and deceleration to move the second member to a next incremental point between points of a position profile in specified periods of time and to enable reversal of direction to return to a starting position;

wherein moving the second member relative to the first member alternately places an aspiration opening of the device into fluid communication with or out of fluid communication with a tissue environment;

wherein the second member is automatically controlled such that there is a hold period at least at some occurrences of the aspiration opening being in fluid communication with the tissue environment, an optimum hold period determined from a function of a suction rate and a length of the second member.

8. The method ofclaim 7 wherein each point of the position profile corresponds to a position where the aspiration opening of the device is in fluid communication with the tissue environment.

9. The method ofclaim 7 wherein moving the second member relative to the first member comprises rotating the second member relative to the first member.

10. The method ofclaim 7 wherein automatically controlling the movement of the second member includes accelerating and decelerating the second member to cause a number of rotations of the second member relative to the first member, and then reversing the direction of rotation of the second member.

11. The method ofclaim 7 wherein the second member is automatically controlled such that the second member is slowed down or stopped when the aspiration opening is in fluid communication with the tissue environment.

12. The method ofclaim 7 wherein moving the second member relative to the first member comprises reciprocating the second member axially relative to the first member.

13. The method ofclaim 7 wherein automatically controlling the movement of the second member using position control methodology includes using a stop position or point of shaft reversal of the second member to compute acceleration or deceleration needed to move between points of a position profile.

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